<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let year = prompt('请输入年份:')
        if(year %4 ==0 && year % 100 > 0){
            document.write(year +'年是闰年')
        }if(year %400 ==0){
            document.write(year +'年是闰年')
        } else {
            document.write(year +'年是平年')}
    </script>
</body>
</html>